1. Field of the Invention
The present invention relates to a camera module which moves a lens.
2. Description of the Related Art
Generally, mobile phones are provided with high resolution compact camera modules having several megapixels. Differentiated high resolution compact digital camera modules require an auto-focusing function or optical zoom function to embody high image quality despite having a comparatively small size.
In conventional camera modules that have a comparatively low number of pixels, a lens group is fixed with respect to the direction of an optical axis so as to reduce the production cost or the size of a product. Therefore, conventional camera modules cannot embody an optical zoom function but can only adjust the magnification of the lens group in such a way (called a digital zoom function) that an electric signal of an optical image is enlarged by an image sensor and an image processing chip.
Although the auto-focusing function or the optical zoom function are already generalized in existing digital cameras, it is still difficult to embody them in compact digital camera modules that are reduced in size to several tens of millimeters in length and width. For example, when taking a picture in an afocal mode, the lens group must be fixed without moving. In a macro or close-up mode in which the lens group is close to a target when taking a picture, the lens group must move in the direction of the optical axis to conduct an auto-focusing function.
To realize the auto-focusing function or the optical zoom function in a compact camera module that is reduced in size, it is required to innovatively improve the drive mechanism including an actuator.